Absorbent articles such as sanitary napkins, pantiliners, and incontinent pads are designed to absorb and retain liquid discharges from the human body and to prevent body and clothing soiling. In order to prevent soiling, such absorbent articles must be securely maintained in close proximity to and in conformity with the body of the wearer. The maintenance of the article against the body is known as "good body contact". Good body contact enables the absorbent article to absorb the vast majority of body fluids before they have an opportunity to flow quickly along the top surface of the article or the skin of the wearer, thereby preventing clothing and body soiling.
In order to securely maintain such absorbent articles in close proximity to the body of the wearer, it has become common for sanitary napkins and other absorbent articles that are designed to be worn in the crotch region of an undergarment or other garment to be secured in the crotch region by adhesive attachment means. The adhesive attachment means usually comprise a pressure sensitive adhesive disposed on the bottom surface of the article.
While absorbent articles having adhesive attachment means are convenient and comfortable, these products continue to suffer from certain disadvantages such as the risk of body and clothing soiling. It has been found that such absorbent articles are subjected to several forces during use. For example, forces are exerted on the lateral edges of the absorbent article when the article is initially placed in the garment as it conforms to the anatomical contours of the body. Movements of the wearer during walking or sitting also subject the absorbent article to applied forces such as sheer stress and torque. In addition, movements of the legs of the wearer tend to apply compression forces along the lateral and the longitudinal edges.
These applied forces during use tend to distort and bunch the center and the edges of the absorbent article, thereby causing a temporary loss of good body contact. Bunching is defined as the formation of wrinkles along either the lateral or longitudinal axes of the article. While some small amount of initial bunching along the longitudinal side edges is desirable so that the article initially creates good body contact, the resulting change in shape and wrinkles along the axes of the article brought about by bunching tend to cause the article to lose contact with the body along the troughs of the wrinkles. Body fluid can thereby easily flow along the troughs of the wrinkles resulting in an increased risk of body and garment soiling.
In addition to body and garment soiling, additional problems result from the application of forces to an absorbent article having adhesive attachment means. During movement by the wearer, the absorbent article may actually become unattached from the garment and then reattach itself. Forces which tend to distort and bunch the article also cause the article to dislodge and shift within the garment causing a loss of coverage against soiling and discomfort for the wearer. Bunching of the article may be severe enough for the article to be distorted such that the adhesive attachment means may make contact with itself and prevent the napkin from reattaching to the garment. This "sticking together" phenomenon provides less area coverage resulting in less protection against soiling and troughs that are uncomfortable for the wearer.
Several different patterns of adhesive attachment means have been developed in response to these problems. For example, U.S. Pat. No. 3,044,467 issued to Campau on July 17, 1962; U.S. Pat. No. 3,672,371 issued to Roeder on June 27, 1972; U.S. Pat. No. 3,897,783 issued to Ginocchio on Aug. 5, 1975; U.S. Pat. No. 3,888,255 issued to Shah, et al. on June 10, 1975; U.S. Pat. No. 4,333,466 issued to Matthews on June 8, 1982 and U.S. Pat. No. 4,445,900 issued to Roeder on May 1, 1984 discuss adhesive attachment patterns designed to more securely maintain a sanitary napkin within the crotch portion of the garment of the wearer.
While these patterns for adhesive attachment means serve to protect against the disadvantages caused by the applied forces, none of the structures referenced above provide the advantages of the adhesive attachment means disclosed and claimed herein. Reduced bunching and good body contact remain as key design considerations. Accordingly, adhesive attachment means providing for better securement of the article within the crotch portion of a garment while minimizing bunching and its effects have been sought.
It is, therefore, an object of the present invention to provide an absorbent article with adhesive attachment means that provide improved securement in the crotch portion of a garment.
It is another object of the present invention to provide adhesive attachment means that more securely maintains the absorbent article in close proximity to and in conformity with the body of the wearer, thereby reducing the risk of body and garment soiling.
It is a further object of the present invention to provide adhesive attachment means that will minimize bunching and distortion of the absorbent article during use.
It is a still further object of the invention to provide adhesive attachment means that will secure the article in the crotch portion of a garment while minimizing the problem of the adhesive sticking to itself during wear.